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COPYRIGHT DEPOSIT. 



THE 

PRAXIS OF URINARY ANALYSIS. 

A GUIDE TO THE CHEMICAL 
ANALYSIS OF URINE. 

WITH DIRECTIONS FOR PREPARING ARTIFICIAL 

PATHOLOGICAL URINES FOR PRACTICING 

THE VARIOUS TESTS 

AND 

AN APPENDIX ON THE ANALYSIS OF 
STOMACH CONTENTS. 



BY 

De. lassae-cohn, 

Professor in the University of Koenigsberg. 



AUTHORIZED TRANSLATION FROM THE AUTHOR'S 

ENLARGED AND REVISED SECOND EDITION 

BY 

H. W. F. LOKENZ, A.M., Ph.D. (Berlin), 

Late Instructor of Organic Chemistry in the 
University of Pennsylvania. 



FIRST THOUSAND. 



» J 9 » 



NEW YORK : 

JOHN WILEY & SONS. 

London: CHAPMAN & HALL, Limited. 

1903. 



& 



S-\ 



THE LIBRARY OF 
CONGRESS, 

Two Copies Received 

JUN 24 1903 

Copyright Entry 
)^tc^ ±~\<\ $> 
CLAS& 0u XXc. No 

S \ o I 6 

COPY B._ 



Copyright, 1903, 

BY 

H. W. F. LORENZ. 



ROBERT DRUMMOND, PRINTER, NEW YORK. 



AUTHOR'S PREFACE TO THE FIRST 
EDITION. 



In the following pages the attempt is made to treat 
the Analysis of Urine and the Stomach Contents, which 
are generally given an unjustified exceptional position, 
in the same manner as a chemical investigation of 
any other material. We will confine ourselves to the 
chemical determinations of those constituents of urine 
and the stomach contents which are of value for diag- 
nosis, following exactly the plan of most text-books 
en other chemical analyses. Just as the latter do not 
consider the rare elements, as they are hardly ever 
encountered in practice, and thereby avoid an excessive 
complication of methods, we also will omit the deter- 
mination of the rare constituents and only consider 
that which experience has shown is sufficient for the 
practical purposes of the analysis of urine and the 
stomach contents. 

The Author. 

KoNIGSBERG, 1897. 



PREFACE TO THE SECOND EDITION. 



In the necessity of giving out a new edition of the book 
within six months after its first appearance, the author 
believes he can see a proof of the need of such a book for 
those circles that have not made and do not make a 
specialty of urinary analysis. 

Munich, 1898. 

iii 



TRANSLATOR'S PREFACE. 



In presenting this little book to the English-reading 
public the translator feels sure that it will meet with 
the same favorable reception that it has received in the 
original language. The author is a practical expert on 
the subject; and the methods given for analysis embrace 
all that is necessary for the purposes of the practical 
physician. 

The translator desires to call particular attention 
to the preparation and use of artificial pathological 
urines. 

Springfield, Ohio, May, 1903. 



iv 



CONTENTS. 



Preface 

Introduction . 



PAGE 

iii 
. 1 



URINARY ANALYSIS. 

A. 
QUALITATIVE TESTS. 

1. Detection of albumen 11 

2. H " sugar 15 

3. " " acetone 19 

4. " " acetoacetic acid . 20 

5. " " bile-pigment 21 

6. " " urobilin 22 

7. " ll blood-pigment 24 

8. " ' ' indican 25 

9. lt " sulphuric acid 28 

10. " il ester-sulphuric acids 28 

11. " tl chlorine '. 32 

12. Phosphates in urine 32 

13. Ammonia in urine 35 

B. 
QUANTITATIVE METHODS. 

1. Quantitative estimation of albumen 37 

2. " " "sugar 38 

3. tl " " total sulphuric acid and ester- 
sulphuric acids 40 

C. 

NORMAL URINE 43 



vi CONTENTS. 

II. 

ANALYSIS OF STOMACH CONTENTS. 

PAGE 

1. Detection of hydrochloric acid 46 

2. " " lacticacid 48 

3. " " volatile acids 49 

4. Test for absence of pepsin 51 

Alphabetical list of all the reagents required 53 

Reagents used in urinary analysis 54 

Reagents and apparatus for the quantitative, etc., estimation 

of constituents of urine 55 

Reagents used in the analysis of stomach contents 56 



INTRODUCTION. 



Urinary analysis, an important contiguous field 
between medicine and chemistry, is still regarded by 
a great number of physicians and chemists as a part of 
their work with which they cannot feel familiar for want 
of sufficient preparation, since they have only busied 
themselves thoroughly with one of the above-mentioned 
sciences. This is certainly deplorable for physicians, 
and also their patients. The former often thus deprive 
themselves of their most valuable aid. 

There is certainly no lack of text-books on urinary 
analysis. Some of them are unexcelled for scientific 
purposes, and it is not the aim of the author to increase 
their number by writing a similar one. In recent years 
almost all these books have been written by medical men, 
or revised by them for many years. Judged by these 
works, most authors seem to think it a scientific task 
to make even the simplest urinary analysis. Instead 
of giving lucid directions for analysis, most of them 
present a series of innumerable reactions that can be 



2 INTRODUCTION. 

made with urines containing abnormal constituents. 
Consequently urinary analysis assumes apparently 
astonishing dimensions and seems to be only feasible 
for physicians having a thorough chemical knowledge, 
but absolutely impracticable for chemists. 

The few directions for urinary analysis which are 
found in some analytical works on general analysis 
written by chemists are even less intelligible. Some 
of them are entirely useless, for, according to their 
directions, it is often quite impossible to decide whether 
a urine contains, say sugar, or not, to say nothing of 
other constituents. It is stated in such a work which 
appeared in 1895 in its sixth edition, and which likewise 
gives entirely inadequate directions for urinary analysis : 
"The examination of urine and urinary calculi is a 
frequently reoccurring work. Its skillful execution 
brings fame and rich pecuniary reward to the practicing 
expert/ ' From this can be judged the esteem in which 
a really reliable urinary analysis is held by many. 

The supposition that the chemical analyses of urine 
and -the stomach contents are particularly difficult, 
which is fostered by all this, is in nowise justified by 
facts. Let us first inform ourselves as to the object 
of such analyses on the part of the practitioner. The 
practicing physician and the chemist desire to know 
whether a urine contains, for instance, albumen or 
sugar, or is free from these. The relation is hence 



INTRODUCTION. 3 

exactly similar to that of the chemist who quite fre- 
quently desires to know if a substance contains chlorine. 
The chemist always * tests for chlorine in the form of 
silver chloride. He learns this the first day that he 
takes up the subject of analytical chemistry. The 
result is that he not only soon masters absolutely this 
method of detecting chlorine, but he also knows in time 
the precipitate of silver chloride, its behavior and 
appearance in such a way that it is impossible for him 
to mistake it for anything else. Every variation from 
its common behavior, which points to some other 
substance, must attract his attention. Of course 
chlorine can be detected in many other ways than in 
the form of silver chloride. But no matter to how 
profitable scientific investigations this study of chlorine 
reactions can lead, it is and always remains the object 
of the analyst to be able to say, with infallible cer- 
tainty, whether a substance investigated by him con- 
tains chlorine or not. 

In the chemical analysis of urine practical physicians 
must likewise make up their minds to regard their 
task in a corresponding manner. Such an analysis, 
dealing as it does with a liquid, is thereby made very 
easy in comparison with a general chemical analysis. 
Physicians must not desire to attempt apparently 

* Exceptions are so rare that they need hardly be considered. 



4 INTRODUCTION. 

scientific investigations with urines in the way of all 
possible kinds of reactions. Even the best water 
analysis for practical purposes made by a chemist, for 
instance the determination of the suitability of a water 
for drinking purposes, or the analysis of a granite, is 
in our day no longer regarded as a scientific feat. 

If physicians, chemists, and apothecaries will always 
make their urinary analyses according to one well- 
recognized method for every single constituent of 
urine, they also will gain such a confidence in their 
work, by such continued practice, that they will no 
longer feel doubtful — and this is a very important 
point — whether the sought-for constituent is present 
or not. The paralyzing uncertainty, which is other- 
wise combined with the distrust of their own ana- 
lytical results, is then soon lost. They must not 
try to vary the methods unless they are experts, 
otherwise the most remarkable things may be found. 

For the practice of a physician it is only necessary 
to prove the presence or absence of the following few 
substances in urine. This must be emphasized espe- 
cially for the benefit of chemists who are in the habit 
of greatly overestimating their number. The urine is 
tested for albumen, sugar, acetone, acetoacetic acid, 
bile-pigment, urobilin, blood, indican, and ester sulphuric 
acids. In certain cases it is not unimportant to test for 
normal constituents like sulphuric acid, chlorine, etc. 



INTRODUCTION. 5 

The physician and chemist must also pay attention 
to the phosphoric acid and ammonia. These will hardly 
ever have any diagnostical importance, but we will 
meet with phosphates in testing for abnormal bodies in 
urine, since they give rise to disturbing secondary 
reactions. Ammonia will be of interest to us on ac- 
count of its influence on the real behavior of urines 
when testing for sugar. 

Larger works on urinary analysis must be consulted 
when urines are encountered which cannot be under- 
stood according to the methods herein given. Years 
may pass before such urines are met with, and some 
analysts may never come across them. 

Urines possessing apparently quite remarkable sec- 
ondary properties occur after the administration of 
medicines to patients. In their case also larger works 
should be consulted. Such urines are seldom found 
outside of clinics, for most urines of sick persons are 
generally analyzed before treatment by the physician, 
who is, of course, supposed to regulate his method of 
treatment by the result of the analysis. 

Practice is hence necessary in urinary analysis the 
same as in any other reliable analysis. Let the few 
qualitative methods described later on be practiced until 
they are completely mastered, which will not take much 
time, i.e., until convinced to one's own satisfaction that 



6 INTRODUCTION. 

one feels sure in their manipulation and interpretation. 
The practice of a physician and apothecary will in time 
furnish them with the various abnormal urines. In 
order to afford chemists the possibility of self-instruction 
in places without clinics and hospitals, the author will 
state under the separate pathological urines how they 
can be prepared artificially from healthy urines by 
adding various substances to the latter. Excepting 
those containing bile-pigments, such artificial urines 
can be easily prepared by methods which are in part 
original with the author. 

A connected course of instruction in urinary analysis is 
only possible with the aid of such artificial pathological 
urines. Each kind cannot be gotten every day even in 
large clinics. It may be remarked further that physi- 
cians often make a microscopical examination of urinary 
sediments (the solid substances gradually precipitated 
from urines) besides the chemical analysis. This 
examination does not offer any particular difficulties as 
far as the commonly occurring constituents, which are 
not very numerous, are concerned. The examination 
of these sediments cannot be discussed here; excellent 
guides for their microscopical analysis can be found in 
many text-books on urinary analysis. 

The elementary nature of practical urinary analysis 
(and particularly of the analysis of the stomach con- 
tents) and the extreme simplicity of its methods will 



INTRODUCTION. 7 

mostly surprise chemists, because it does not come up 
to their expectations. Almost all the tests can be 
made in a test-tube and permit the presence or absence 
of the more common pathological constituents to be 
proven in a few minutes. It must not be supposed that 
the directions to be given here are too brief. In the 
course of many years of teaching students and giving 
courses participated in by old, experienced physicians 
with a practice of thirty years and more, the author 
has convinced himself that the following methods of 
analysis of urine and stomach contents fully suffice for 
the purposes of the practical physician. 

The following may be remarked concerning the 
methods given for analysis: Methods have been chosen 
which exclude every ambiguity and are nevertheless 
as convenient as possible. The so-called boiling method 
is used, for instance, to detect albumen. The author 
is well aware that cold tests are also known, which do 
away with the trouble and time required by boiling 
urine. Thus nitric acid, acetic acid, and potassium 
ferrocyanicle solution give precipitates with urines 
containing albumen in the cold; but who can say 
positively that among all those bodies that can possibly 
occur in urine, there are not at times some which also 
give precipitates with nitric acid, acetic acid, and 
potassium ferrocyanide solution (the latter precipitates 
many bases). These bodies may come from a food 



8 INTRODUCTION. 

seldom eaten or from a medicine and may thus give 
rise to mistaking them for albumen. 

The boiling test for albumen excludes all mistakes 
because dissolved albumen is the only known substance 
that always coagulates when urine is boiled and then 
slightly acidified, and hence makes it turbid (see the 
exceptions, p. 12). 

Exempla docent. The author will take the liberty 
to relate the following personal experience showing 
to what the use of promiscuous tests, as found in books 
by the dozen, will lead on the part of those who are 
unable to properly discriminate. A young physician 
asked him one day to test a certain urine for albumen. 
It proved to be free from it. The physician was much 
astonished, for he had believed that he had found 
albumen in the urine of his patient for five years. 
During this whole time the latter showed no unfavorable 
symptoms, as might be expected from this discovery. 
He, therefore, had asked the author to make an analysis. 
When asked how he had tested for albumen, he said 
that he used for this purpose a solution of picric acid 
which was especially recommended in English text- 
books. The acid had always given a precipitate in the 
urine on standing for some time, which he regarded as 
showing the presence of albumen. The author could 
give him this reply: Then you think, perhaps, that 
you have found albumen in a large part of your rich 



INTRODUCTION. 9 

practice, while your poor patients must seem much 
healthier in this regard? He admitted this. The 
explanation is as follows: Picric acid precipitates 
albumen; this is undoubtedly true. "We shall see how 
conveniently this fact can be used in quantitative albu- 
men determinations. But the acid also precipitates a 
normal constituent of urine, creatinine. It combines 
with this to form a double compound, potassium 
creatinine picrate, which is practically insoluble in 
cold urine, and hence gradually precipitated. The 
physician mistook this slowly formed precipitate for 
albumen, and as creatinine occurs in richer quantities 
in urine when meat is eaten than otherwise, the urines 
of well-to-do people in most cases contain more of this 
substance than the urine of the poorer classes. The 
urines of the former, hence, become turbid more easily 
than those of the latter when picric acid is added, even 
when albumen is absent. 

What little information for diagnostical purposes that 
can be determined by a chemical analysis of stomach 
contents will be appended to the urinary analysis. The 
same can be said of the methods given in the appendix 
as of those under urinary analysis. 



THE PEAXIS OF ITKINABY ANALYSIS. 



I 

URINARY ANALYSIS. 



QUALITATIVE TESTS. 

1. Detection of Albumen. 

Fill a test-tube one-third full with the clear urine * 
(about 8-9 cc. are required) and heat the contents to 
complete boiling. The urine remains clear or becomes 
turbid. Now add two or three drops of an approxi- 
mately 10 per cent, acetic acid and shake. If the urine 
becomes clear again on this addition, the turbidity is 
caused by earthy phosphates (see p. 32) and is of no 
significance. Should it remain cloudy, or should the 
turbidity increase when the acetic acid is added, albumen 
is present. 

If any doubt exists about a slight cloudiness in a 

* Filtered, if necessary. 

11 



12 THE PRAXIS OF URINARY ANALYSIS. 

urine which has been thus treated, the latter is com- 
pared with a sample of the unboiled, clear urine in a 
second test-tube. This comparison will easily show 
the presence or absence of any cloudiness. This test 
fails only when the urine is turbid at the start and 
it is impossible to decide, after boiling and adding acetic 
acid, whether the turbidity has been increased or not 
by the precipitation of traces of albumen. In this case 
also the urine must first be clarified. Ordinary filtra- 
tion will not suffice, because the fermentation bacteria 
which cause the turbidity pass through the pores of 
the filter-paper, the other suspended particles remaining 
on the filter. Proceed as follows: Place about 2 cc. 
of crude infusorial earth in a test-tube, fill the latter 
almost full with urine and shake thoroughly. Now 
filter through ordinary filter-paper. If the first filtrate 
is not quite clear pour it back on the filter. An abso- 
lutely clear filtrate will soon be obtained. This is 
divided into two equal parts and the one tested for albu- 
men, as above mentioned. If the boiled, acidified solution 
is then compared with the other half of the filtrate, it 
will be easy to detect by comparison even a very slight 
trace of albumen, as shown by an eventual cloudiness 
in the boiled urine. 

Note. On account of the importance of the albumen 
test for diagnosis it may be remarked here, for the 
sake of completeness, that a urine which has been 



URINARY ANALYSIS. 13 

tested according to this method may appear cloudy 
although free from albumen, when the patient has 
used the following internally or externally : turpentine, 
copaiba, cubeb, santal oil, styrax, or petroleum. The 
turbidity is then caused by resin acids which have 
passed into the urine by the use of these remedies and 
are precipitated by the acetic acid. These resin acids 
are detected as such by adding considerable alcohol to 
the boiled urine. They are dissolved by the alcohol; 
coagulated albumen is not. The author may say that he 
has never come across such urines although he has 
made thousands of urinary analyses. 

Artificial Albumen Urine. — This is made in the follow- 
ing manner: The white of an egg (about 20 cc.) is 
diluted with water to 100 cc. and well shaken. When 
no graduated vessel is at hand the proportion may 
be estimated by the eye. The liquid is filtered from 
suspended particles. If 5 drops of such a clear solution 
are added to 100 cc. of normal urine and the albumen 
test is made as described, a very perceptible turbidity 
is produced which differs in no way from that seen in 
the case of natural albumen urines. 20 drops give a 
flocculent precipitate, and when 50 drops are taken it 
is very flocculent, more so than is seen even in natural 
urines much richer in albumen. 

It may be remarked that almost all urines can be 
kept indefinitely in a stoppered bottle if preserved with 



14 THE PRAXIS OF URINARY ANALYSIS. 

some chloroform, the mixture having been thoroughly 
shaken. When thus treated, urines will give the re- 
actions unchanged even after the lapse of many years. 
This is of great advantage to the study of urinary 
analysis, for urines can thus be kept on hand for practice 
and comparison. 

Artificial Phosphate Urine. — Urines which become 
turbid on boiling by the precipitation of earthy phos- 
phates (for reasons see p. 32, under Phosphoric Acicl) 
are not met with so frequently as such which do not 
possess this property. Urines which are voided when 
much meat is eaten and little is drank are more 
liable to show this behavior. Any freshly voided 
urine can be given this property of becoming turbid 
on boiling, even when albumen is entirely absent, by 
shaking it with an excess of freshly precipitated calcium 
carbonate and filtering. The urine will hereby become 
so rich in lime that it will become turbid on boiling, 
calcium phosphate being precipitated. This cloudiness 
is dissolved when acetic acid is added as opposed to the 
precipitate of coagulated albumen. 

The calcium carbonate for this purpose is prepared 
by adding a solution of sodium carbonate to a solution 
of calcium chloride in a test-tube. Part of the pre- 
cipitated calcium carbonate soon settles to the bottom. 
The supernatant liquid is decanted, more water is 
added, and shaken. As soon as the precipitate has 



URINARY ANALYSIS. 15 

again subsided the liquid part is again poured off. 
Repeat this operation again and then pour the calcium 
carbonate precipitate into the urine. 

In order to learn the manipulation with infusorial 
earth a urine is allowed to stand exposed to the air 
for several days in an open vessel. Strong decomposi- 
tion soon occurs. The use only of filter-paper in the 
usual way will no longer give a clear filtrate with such a 
liquid. But this can be accomplished by using in- 
fusorial earth as directed on page 12. 

2. Detection of Sugar. 
The sugar occurring in the urine of persons afflicted 
with diabetes is grape-sugar. The best method by far 
for its detection is the test mentioned by Trommer. In 
making the test no deviation in any particular must be 
made from the following directions, otherwise the results 
will be uncertain. Urines which are to be tested fcr 
sugar must be free from albumen, or contain at the 
most only traces of albumen, since these do not interfere 
with the test. If they contain any considerable quantity 
of albumen, a few more cubic centimeters of urine than 
are necessary for making the albumen test are heated 
to boiling in a test-tube, two to three drops of acetic 
acid are added, and the precipitated albumen filtered 
off. The filtrate which is free from albumen is allowed 
to cool and then tested by Trommer's method. 



16 THE PRAXIS OF URINARY ANALYSIS. 

Trom?ner's Test— Fill a test-tube one-third full with 
the urine which is free from albumen and then add 
almost as much of a 10 per cent, sodium hydrate solution 
(do not be saving with the sodium hydrate solution). 
The turbidity which is formed by this addition is again 
due to earthy phosphates (see p. 33), and is of no 
consequence. Now pour into the mixture, drop by 
drop, an approximately 5 per cent, copper sulphate 
solution. The blue precipitate of cupric hydrate which 
is formed dissolves with a dark -blue color, when grape- 
sugar is present, as soon as the liquid is shaken. The 
most important thing about the whole test is that the 
addition of copper sulphate solution must not be dis- 
continued until the cupric hydrate, which is at first 
precipitated, is no longer dissolved on shaking and the 
solution is cloudy from a slight excess of the hydrate, 
aside from the turbidity caused by the phosphates. 

Unless careful attention is paid to the above point 
the test becomes entirely unreliable when small quanti- 
ties of sugar are present. This final turbidity which 
is caused by the cupric hydrate must not be too heavy. 
With a little practice the proper amount can easily be 
judged. 

Now heat the blue liquid over a Bunsen burner. If 
yellow clouds of cuprous hydrate * are precipitated 

* When Trommer's test is made for practice with an aqueous 



URINARY ANALYSIS. 17 

before boiling, the presence of sugar is proven; if 
they appear only on boiling, less sugar is present. If 
the urine is decolorized, but the yellow cuprous hy- 
drate is not precipitated until after standing for some 
time, the quantity of sugar in the urine is not very 
large, according to this manner of making the test. 
Very slight subsequent precipitations of cuprous hydrate 
are no proof whatever for sugar, because every normal 
urine (see p. 43) contains small quantities of reduc- 
ing substances (viz., uric acid and creatinine reduce 
under these conditions). 

If there is any doubt, after making the test, about 
the patient having diabetes or not, the following pro- 
cedure seems best for the practicing physician, accord- 
ing to the author. He permits the patient to partake 
of a meal which is particularly rich in starch (bread, 
potatoes, rice) and sugar. The urine voided in the two 
hours following such a meal is tested by Trommer's 
method. If this urine also has only slightly reducing 
properties the patient is not suffering from diabetes. 
If sugar is found, however, continued investigations 
will easily decide if it is diabetes or an alimentary 
glycosuria. 



solution of grape-sugar, red cuprous hydrate is always obtained. 
Urine containing sugar, on the contrary, gives the yellow modifica- 
tion, except in very rare cases. It is not known what substances in 
urine give rise to this behavior. 



18 THE PRAXIS OF URINARY ANALYSIS. 

The amount of sugar in the urine of diabetic persons 
varies very considerably in the course of a day, so long 
as they do not heed a prescribed diet. Hence in slight 
cases the morning urine may hardly contain any sugar, 
and the quantity voided after a meal rich in carbo- 
hydrates and sugar still be considerable. 

On acount of this fact many physicians make a 
quantitative as well as a qualitative test for sugar in 
an average sample taken from the urine voided in the 
course of twenty-four hours. This plan may also be 
recommended to chemists. 

It may be remarked that every trace of grape-sugar 
can also be determined with phenylhydrazine. This test 
excels that of Trommer, but is perhaps too delicate. 
It requires about a half hour's time and a later examina- 
tion of the precipitated sediment under the microscope 
to see if the clusters of the phenylglycosazine are present 
in the sediment, a test that is considerably more in- 
convenient for the physician. 

Artificial Sugar Urine. — This is made by adding a 
solution of grape-sugar to normal urine. The latter 
will also then give the yellow cuprous hydrate. By 
adding various quantities of the sugar solution it will 
soon be possible to judge whether a trace, little, or 
considerable sugar is present in urine, and for practical 
purposes the phenylhydrazine will not be necessary. 



URINARY ANALYSIS. 19 

3. Acetone and Acetoacetic Acid. 

In the later and more severe stages of diabetes acetone, 
acetoacetic acid, and often oxybutyric acid, besides 
sugar, are present in considerable quantities in the 
urine. Only the first two of these substances can be 
easily detected, and their detection is sufficient for 
diagnosis. 

The oxybutyric acid must be prepared as such in 
order to prove its presence. This requires at least a 
week's time and the equipments of a laboratory. The 
oxybutyric acid can also be recognized by the lsevo- 
rotation of the urines containing it (see p. 39). For 
this purpose the urines must first be freed from sugar 
by fermenting the latter with yeast (see p. 39). 

Detection of Acetone. — Pour about two cubic centi- 
meters of water upon a few crystals of sodium nitro- 
prussicle contained in a test-tube, and shake until the 
solution becomes strongly colored. This solution,* 
which must not be too dilute, is poured into some urine 
and sodium hydrate is added. On addition of the 
latter every urine is colored red, for this red color is 
caused by creatinine, which is always present in normal 
urine, as well as by acetone. To determine the presence 
of acetone aside from the creatinine add immediately a 

* It must always be freshly prepared, because it does not keep 
very long. 



20 THE PRAXIS OF URINARY ANALYSIS. 

very copious amount of glacial acetic acid. If the color 
of the liquid grows a darker red, a so-called Bordeaux 
red, acetone is present; if the red coloration again dis- 
appears when glacial acetic acid is added, the color was 
due to creatinine only. 

This method for the detection of acetone does not 
indicate those traces of acetone which are present in 
every normal urine. 

On standing some time the solution turns green, 
the creatinine, in the presence of glacial acetic acid, 
begins to decompose the sodium-nitroprusside. This 
has nothing to do with the acetone test. 

It may be remarked that urines rich in acetone have 
a fruit-like odor, which is due to the acetone. The 
breath of such patients also smells of acetone. Ace- 
tone was found in urine by Petters in 1857. 

Artificial Acetone Urine. — This is prepared by adding 
a little acetone to a healthy urine. 

4. Detection of Acetoacetic Acid. 

Dilute ferric chloride solution is added drop by drop 
to urine. The first drops cause a whitish precipitate 
of iron phosphate in any urine, additional drops a 
dark red (wine-red) coloration, which can be particularly 
seen in transmitted light. 

When a urine contains only small quantities of aceto- 
acetic acid it will sometimes appear doubtful if any 



URINARY ANALYSIS. 21 

acetoacetic acid is present, since the color is then not 
very marked. In such cases, if the same test is made 
with a normal urine and the two test-tubes are com- 
pared with one another, it is not difficult to decide on 
the presence or absence of acetoacetic acid. Gerhard 
declared in 1865 that the red color of some urines on 
addition of iron chloride was caused by acetoacetic 
ester, later it was shown that it is free acetoacetic acid 
which imparts this color. 

Since commercial acetoacetic ethyl ester gives the 
same test as acetoacetic acid an artificial urine giving 
this reaction can be obtained by adding a few drops 
of acetoacetic ethyl ester to a normal urine. They sink 
to the bottom, but are readily dissolved by stirring. 

5. Detection of Bile-pigment. 

Urines containing bile-pigments have a dark ap- 
pearance and give a yellow foam when shaken. 

For a stock solution prepare a mixture of 95 parts 
of a 25 per cent, solution of nitric acid with 5 parts of 
fuming nitric acid, and add 30 parts of water. This 
mixture contains a copious amount of nitrous acid for 
the test. 

Two cubic centimeters of this mixture are placed in a 
test-tube and the urine is poured down the side of the 
inclined tube, when it will run above the acid mixture 



22 THE PRAXIS OF URINARY ANALYSIS. 

and form a clear layer on top of this. On the border 
of the two liquids color zones appear, but only a green 
ring is decisive for bile-pigments. 

This not exceedingly delicate test can be made more 
so in the following manner: Filter through a filter- 
paper larger quantities of urine in which bile-pigments 
are supposed to be present, or filter the same quantity of 
urine several times through the same filter-paper. 
The fibers of the paper retain the bile-pigments and 
repeated filtration of the same portion increases the 
quantity retained. After all the urine has run through 
the filter the latter is laid on some dry filter-paper, 
which will absorb the greater part of the liquid still 
remaining. The paper is now treated with a drop of 
the nitric-nitrous acid mixture on the end of a glass 
rod. Colored rings are formed around these spots, of 
which the green ring is typical of bile-pigment. 

Artificial Bile-pigment Urine cannot be prepared 
very well. Urines to which bile -pigments, prepared 
from gall-stones, have been added behave differently 
from natural bile-pigment urine. The addition of gall 
is useless. 

6. Detection of Urobilin. 

Urobilin, which was discovered by Jaffe in 1868, occurs 
in pathological urines with bile -pigments, but also in 
their absence, in quantities determinable by direct 



URINARY ANALYSIS. 23 

methods. Its detection has sometimes a diagnostical 
value. 

Fill a test-tube three-fourths full with urine and 
acidulate with one drop of hydrochloric acid. Now 
add 4-5 cc. amyl alcohol. Shake the mixture carefully 
6 to 8 times (otherwise an emulsion is formed). The 
amyl alcohol which takes up the urobilin soon separates 
again in a layer above the urine. Particles suspended 
in the alcohol are crushed with a glass rod, if necessary, 
and they will sink to the bottom. It will thus be possible 
after a few minutes to pour off about 3 cc. of the amyl 
alcohol into another test-tube. Dilute the alcoholic 
extract with double the quantity of 96 per cent, alcohol. 
Now add to this solution about 1 cc. of a 5 per cent, 
alcoholic zinc chloride solution, and then a drop of 
ammonia. The later neutralizes the small amount 
of hydrochloric acid taken up by the amyl alcoholic 
solution in making the extraction. The addition of 
this ammonia is very necessary. However, some zinc 
hydrate is precipitated. If this is filtered off, the solu- 
tion shows a green fluorescence when urobilin was present 
in the urine. This fluorescence disappears when a trace 
of acid is added. 

Artificial Urobilin Urine. — This is prepared from 
fresh human faeces, which always contain a considerable 
amount of urobilin. Pour on these 96 per cent, alcohol, 
avoiding an excess, in order to obtain a concentrated 



24 THE PRAXIS OF URINARY ANALYSIS. 

solution, and filter after stirring thoroughly. The 
red-brown filtrate, which will keep only several months, 
is made slightly turbid by adding zinc chloride solution. 
When this turbidity is removed by a second filtration 
the liquid shows the green fluorescence excellently. 
In order to become acquainted with the reaction in 
urine an ample amount of the alcoholic feces extract 
is added to normal urine. The latter becomes turbid 
from the alcohol, but this is of no consequence. Make 
the test as described. The green fluorescence is seen 
exactly as in natural urobilin urines. 

If it is desired for instructive purposes to remove 
the turbidity which is caused by the alcoholic extract 
the best method is to treat the urine with some in- 
fusorial earth, to stir thoroughly and filter. The filtrate 
remains turbid, unless infusorial earth is used. It has 
as yet been impossible to remove the feces odor which 
is imparted to the urine by the extract. 

7. Detection of Blood Pigment. 

Make the urine strongly alkaline by adding sodium 
hydrate and heat it to boiling in a test-tube. The 
earthy phosphates precipitated by the alkali soon subside 
on standing and appear colored red (by hematin) if 
blood was present in the urine, which cannot always 
be seen in the urine itself. 

It may be remarked that the slight traces of blood 



URINARY ANALYSIS. 25 

present and which this test does not indicate can be 
seen in the urinary sediment under the microscope. 

Artificial Blood Urine. — This is obtained by adding 
some blood to a normal urine. If blood is dried by 
spreading it on plates and exposing it to the air it can 
be kept for any length of time. This dried blood can 
then be ground in water when needed and the filtrate 
poured into some normal urine. 

8. Detection of Indican. 

Pure chemistry designates as indican the plant 
glucoside, which yields indigo when broken up. In 
medicinal chemistry this name indicates the substance 
which by suitable oxidation of urine yields indigo. 
The two bodies are chemically very different. The 
substance occurring in urine, and which by proper 
treatment yields indigo, is potassium indoxyl sulphate 
(see below). 

To test for indican, fill a test-tube half full with 
urine, add about 2 cc. of chloroform and fill the tube 
almost full with concentrated hydrochloric acid (of 
25 per cent. HC1). Now add, according to Jaffe, 
dilute chlorated lime solution which has been recently 
prepared and filtered, drop by drop, shaking after each 
addition. The indigo formed will be dissolved by the 
chloroform and colors it blue. If more indigo is pro- 



26 THE PRAXIS OF URINARY ANALYSIS. 

ducecl than the chloroform can dissolve it will swim 
as such in the liquid. 

As an excess of chlorated lime again destroys the 
indigo which is formed at first, the following method 
will be more practical for those who are less experienced. 
It necessitates a special reagent, but one that will keep 
indefinitely. In this case also a test-tube is filled half 
full with urine and almost the same quantity hydro- 
chloric acid, containing ferric chloride as an oxidant, 
is added and then likewise about 2 cc. chloroform. 
After shaking frequently, but not too violently (other- 
wise an emulsin is formed), whereby a slight warming 
of the solution is noticeable, the chloroform will be 
colored more or less blue by the indigo which is formed 
in the oxidation of the potassium indoxyl sulphate in 
proportion to the indican originally present. 

The hydrochloric acid-ferric chloride solution for 
this test is made by dissolving 2 g. of solid ferric chloride 
in a half liter of hydrochloric acid, specific gravity 1.19, 
which is equivalent to 36 per cent. HC1. The so-called 
concentrated hydrochloric acid of the apothecaries 
which contains only 25 per cent. HC1 is by far too 
dilute for this purpose. This reaction cannot be 
obtained with it. 

It is perhaps not superfluous, particularly for chemists, 
to remark the following in regard to the cause of the 
occurrence of indican in urine. Albumen breaks down 



URINARY ANALYSIS. 27 

in the intestinal fermentation and yields indol among 
many other substances. This indol is reabsorbed by 
the body and oxidized in the metabolic process like 
all similar substances. The organism combines the 
indoxyl which is formed from it by this oxidation 
immediately with sulphuric acid. This latter compound 
unites further with the alkali of the blood and is finally 
eliminated with the urine as potassium indoxyl sulphate. 
This is the origin of this compound, which is found in 
urine. It occurs in traces in every urine, of which 
fact any one can easily convince himself. Oxidants 
like chlorated lime or ferric chloride-hydrochloric acid 
solution * convert it into indigo. 

The longer the contents of the intestines stagnate, 
especially those of the small intestine, the larger will 
be the amount of indican in the urine. Hence the 
diagnostical interest in its increase, which was first 
proven and explained by Jaffe. 

Artificial Indican Urine. — It is prepared with the aid 

* The ferric chloride acts as an oxidant in such cases, a decom- 
position of the water taking place. Ferrous chloride is formed and 
hydrochloric acid and oxygen become available. 



2FeCl 3 

Ferric 
chloride. 


+ H 2 = 

Water. 


= 2FeCl 2 
Ferrous 
chloride. 


+ 2HC1 

Hydro- 
chloric 
acid. 


+ 0. 

Oxygen 

available for 

oxidizing 

purposes. 



This is not, however, a method for generating gaseous oxygen. 
The equation expresses the reaction only when some substance is 
present in the acid ferric chloride solution which the oxygen can 
immediately oxidize. 



28 THE PRAXIS OF URINARY ANALYSIS. 

of animal urine. The urine of herbivora is consider- 
ably richer in indican than human urine. The her- 
bivora have a much longer intestine than the carnivora 
in order to better make use of their f ood, which is rich 
in carbohydrates and relatively poor in albumen. A 
much greater fermentation occurs, therefore, in the 
intestines of herbivora, which leads to a greater 
elimination of indican by the urine. If horses' urine 
is evaporated to dryness on the water-bath and the 
residue extracted with alcohol much indican passes 
into the alcohol. If such an extract is filtered after 
standing twenty-four hours, which is then easily ac- 
complished, a solution rich in indican is obtained 
which will keep indefinitely, as the author has been 
able to verify. Only a little of this solution need be 
added to human urine, to become familiar with the 
behavior of indican urine. 

9. Sulphuric Acid. 

Sulphuric acid is detected by acidifying the urine 
with hydrochloric acid and adding barium chloride. 
Barium sulphate is precipitated, which is insoluble 
in all solvents. 

10. Ester Sulphuric Acids. 

To test for ester sulphuric acids in urine, add, in a 
test-tube, a liberal amount of barium chloride to urine. 



URINARY ANALYSIS. 29 

All the sulphuric acid, besides some other substances, 
are precipitated. Now add one or two drops of an 
approximately 10 per cent, soda solution, but only 
enough to obtain a clear filtrate. The soda precipitates 
a little coarsely crystalline barium carbonate, which 
envelopes the fine precipitate of barium sulphate and 
thus prevents it from passing through the filter, which 
would otherwise be the case if barium chloride alone 
were added. 

The solution thus obtained on filtration is free from 
sulphuric acid, but still contains the salts of the ester 
sulphuric acids, for the barium salts of the latter are 
soluble in water, as distinguished from barium sulphate. 

Make the solution in the test-tube strongly acid with 
concentrated hydrochloric acid and boil for some time. 
The contents of the test-tube are hereby soon colored 
red by the action of the hydrochloric acid on the coloring 
matters of the urine and then gradually become turbid 
by the renewed precipitation of barium sulphate. By 
boiling with hydrochloric acid the ester sulphuric acids 
are decomposed into their components. For example, 
phenyl sulphuric acid (see below) is broken up, yielding 
phenol and free sulphuric acid, which immediately 
reacts with the excess of barium chloride present in the 
solution and is precipitated as barium sulphate. This 
splitting up of the ester sulphuric acids, which is the 
cause for the formation of free sulphuric acid, is the 



30 THE PRAXIS OF URINARY ANALYSIS. 

reason why the renewed precipitation of barium sul- 
phate takes place when this acid solution is boiled. It 
at the same time proves the presence of ester-sulphuric 
acids in the urine. 

The explanation is as follows: Ester sulphuric acids 
or ethereal sulphuric acids are formed by the union of 
a molecule of an alcohol (in the broadest sense) with a 
molecule of sulphuric acid, with the elimination of a 
molecule of water. 

C 2 H 5 OH + HO-SO,*H = H 2 + C 2 H 5 OS0 3 H. 

Ethyl Sulphuric Water. Ethyl sulphuric 

(ordinary) acid. acid, 

alcohol. 

C 6 H 5 OH + HO-SO.H = H 2 + C 6 H 5 OS0 3 H. 

Phenyl Sulphuric Phenyl sulphuric 

alcohol acid. acid, 

(carbolic acid). 

Urines which contained phenyl sulphuric acid, of 
course in the form of a salt (combined with potassium or 
sodium), could formerly be easily obtained in chirurgical 
clinics when carbolic acid was much used in operations. 
At the present time they are rare. To obtain them for 
practice and instruction purposes it may be necessary 
to feed a large-sized dog about two grams of carbolic 
acid, of course in a very great dilution. He will be 
able to stand this dose very well and without any harm. 
Another method for obtaining such urines which has 
also been recommended is to rub in some concentrated 
carbolic acid on the skin of a dog. 

* Written thus for the sake of perspicuity instead of H 2 S0 4 . 



URINARY ANALYSIS. 31 

Indican, with which we have already become ac- 
quainted in the preceding pages, is also such an ester of 
sulphuric acid, indoxyl sulphuric acid. 

The total amount of ester sulphuric acids in normal 
urine is very small, so that they can hardly be detected 
in the quantities that can be examined in a test-tube. 
To find out if they are almost entirely absent is of the 
greatest importance in some cases. In cancer of the 
intestines it has been said that the operation should not 
be performed until the intestines are evacuated as 
completely as possible. This complete absence of 
stagnant feces is recognized by the almost complete 
disappearance of ester sulphuric acids in the urine. 
These ester acids can hardly be present in urine after 
the intestines have been completely emptied, for lack 
of fermentation phenomena. (See the Quantitative 
Determination of Ester Sulphuric Acids, p. 40.) 

Artificial Ester Sulphuric Acid Urine. — When no dog 
and a suitable cage can be had for the above purpose, 
such a urine can be prepared by adding a solution of 
potassium ethyl sulphate to a normal urine. This salt 
is a commercial article. It may be remarked that the 
decomposition of this ester acid, ethyl sulphuric acid, 
does not occur so rapidly when it is boiled with hydro- 
chloric acid as that of phenyl sulphuric acid and other 
similar ester sulphuric acids found in urine. But 
potassium phenyl sulphate is not on the market and its 



32 THE PRAXIS OF URINARY ANALYSIS. 

preparation too difficult to be recommended here, 
because it is very difficult to obtain good potassium 
pyrosulphate, which is needed for its preparation. 

The ester sulphuric acids are split up into their com- 
ponents by boiling with hydrochloric acid, water being 
taken up under these conditions: 

C 6 H 5 O.S0 3 H + H 2 = C 6 H 5 OH + HOS0 3 H 

Phenyl sul- Water. Phenol. Sulphuric 

phuric acid. acid. 

11. Detection of Chlorine. 

To test for chlorine acidify the urine with nitric acid 
and add an approximately 3 per cent, solution of silver 
nitrate. Silver chloride is precipitated, which can 
be identified by its solubility in ammonia. 

The urine which has thus been made alkaline by this 
addition of ammonia remains, of course, turbid, silver 
chloride being dissolved, but the earthy phosphates 
precipitated. Formerly the estimation of the amount 
of chlorides in urine for diagnostical purposes was 
considered of more importance than at present. 

12. The Phosphates of Urine. 

When phosphorus is burnt it gives, as is well known, 
a white smoke of phosphoric anhydride. This unites 
with three molecules of water to form phosphoric acid, 
which is called ortho- or ordinary phosphoric acid: 
P 2 5 +3H 2 = P 2 8 H 6 , or halved, 2H 3 P0 4 . 



URINARY ANALYSIS. 33 

The formula of ordinary phosphoric acid is therefore 
written H 3 P0 4 , since half of the formula suffices. Its 
salts occur in urine as sodium or potassium phosphates, 
in part as calcium or magnesium phosphates. These 
latter compounds are called earthy phosphates. So- 
dium (potassium) phosphate is soluble in water under 
all conditions. It is, therefore, not seen when urine is 
boiled in the albumen test or w r hen sodium hydrate is 
added in making Trommer's test. The earthy phos- 
phates behave differently. We will explain their be- 
havior by means of the calcium salt, with which that 
of the magnesium salt is identical. 

Phosphoric acid is tribasic, since it contains three 
hydrogen atoms replaceable by metals. Calcium is 
a bivalent metal, and by introducing one atom of cal- 
cium into two molecules of phosphoric acid the com- 
pound Ca(H 2 P0 4 ) 2 is formed. We see this is an acid 
calcium phosphate; acid hydrogen atoms {i.e. re- 
placeable by metals) are still present in the molecule. 
Such acid earthy phosphates are soluble in water, and 
it is principally this calcium phosphate wilich is present 
in urine. 

When Trommels test is to be made and sodium 
hydroxide is added to the urine, this alkali reacts with 
the acid calcium phosphate. There are formed finally 
neutral calcium phosphate and neutral sodium phos- 
phate and water, according to the equations 



34 THE PRAXIS OF URINARY ANALYSIS. 

Ca(H 2 P0 4 ) 2 + 4NaOH = Ca(Na 2 P0 4 ) 2 + 4H 2 

1 molecule acid 4 mol. 1 mol. calcium 4 molecules 

calcium phosphate sodium sodium phos- of water, 

(soluble in water). hydrate. phate (insolu- 

ble in water;. 

and 

3Ca(Na 2 P0 4 ) 2 = Ca 3 (P0 4 ) 2 + 4Na 3 P0 4 

3 mol calcium Breaks 1 mol. neutral 4 mol. sodium 

sodium phosphate up into calcium phosphate phosphate 

(.insoluble in water). (insoluble in water), (soluble in water). 

In neutral calcium phosphate there is no longer present 
a hydrogen atom which is replaceable by a metal, and 
neutral earthy phosphates are insoluble in water. 
They are precipitated from solutions as soon as the 
conditions exist for their formation. They are thus 
always precipitated from a urine when it is made 
alkaline, as required by Trommer's test. 

The reason why the earthy phosphates in a urine 
are precipitated by boiling is as follows, according to 
Stokvis. In slightly acid urines acid calcium phosphate 
of the formula CaHP0 4 can also occur, and solutions 
of this water soluble calcium phosphate CaHP0 4 are 
changed by boiling into neutral calcium phosphate 
which is precipitated, and water soluble di-acid calcium 
phosphate : 

4HCaP0 4 = Ca(H 2 P0 4 ) 2 + Ca 3 (P0 4 ) 2 

4 molecules mon- 1 mol. diacid 1 mol. neutral 

acid calcium calcium phosphate calcium phosphate 
phosphate (soluble). (insoluble), 

(soluble). 

This insoluble calcium phosphate which is precipitated 
is again dissolved when acetic acid is added. 



URINARY ANALYSIS. 35 

13. The Ammonia of Urine. 

Even freshly voided urine contains ammonia, which 
can be shown in the following manner. Pour about 
25 cc. of urine into a small beaker , add milk of lime, 
stir and cover the beaker with a watch-glass having a 
piece of moistened red litmus-paper stuck on its bottom 
side. The paper will be colored blue after a short time 
by the gaseous ammonia vapors which are liberated 
by the milk of lime. 

Sodium hydrate must not be used instead of this 
latter reagent, as the former decomposes the urea which 
is present in quantity in every urine. This decom- 
position occurs even in cold solution and ammonia is 
liberated. Lime milk does not do this. In fact urea 
decomposes very readily, for instance, in the decay of 
urine. Water is taken up and carbon dioxide and 
ammonia are generated: 

/NH 2 
CO 



\NH 3 - H 2 == C0 2 -- 2NH, 

'arbon 
acid. 



2 I J^2 W ~~ ^^2 

Urea. Water. Carbonic Ammonia. 



These unite in turn, taking up a molecule of water, 
to form ammonium carbonate, on which in part the 
strong odor of putrefying urine depends. 

According to the author's observations, the urine 
voided first in the morning is generally quite rich in 



36 THE PRAXIS OF URINARY ANALYSIS. 

ammonia. This is the reason why morning urine always 
dissolves some copper hydroxide in Trommer's test, and 
on this account the ammonia is mentioned here. In this 
case ammonia which, as is known, also dissolves copper 
hydrate with a blue color is the dissolving principle. 
Naturally such a urine gives no clouds of yellow cuprous 
hydrate when heated, nor does it give any appreciable 
amount after it has been boiled, unless sugar is present. 
It cannot have a stronger reducing action than the 
traces of reducing substances can give which occur nor- 
mally in urine. Such urines will have more of a green 
than blue color when only a very little ammonia is the 
cause of the solution of the cupric hydrate. The green 
color is then due to the slightly blue color uniting with 
the yellow of the urine to green. What has been said 
about urine voided in the morning in regard to its 
dissolving property of cupric hydrate is true to a much 
greater degree with decomposed urines, as they are 
very rich in ammonia compounds. 

B. 
QUANTITATIVE METHODS. 

Of quantitative determinations only those of albumen, 
sugar, and ester sulphuric acids are used for diagnostical 
purposes. Approximate estimations suffice in the case 
of indican, etc., i.e. little, much, copious. 



URINARY ANALYSIS. 37 

1. Quantitative Determination of Albumen. 

The quantitative determination of albumen can of 
course be made most accurately by weighing the albu- 
men precipitate, using all possible precautions. This 
method is employed almost exclusively for scientific 
purposes, but hardly for practical purposes because 
albumen precipitates filter badly, and the complete 
drying at 100° and the determination of the ash require 
a great deal of time, besides an analytical balance is 
necessary. 

In practice Essbach's albuminometer is used, which 
is extremely convenient, but not sufficiently accurate 
for scientific purposes. In this instrument the quantity 
of albumen is read off in one-tenth per cents, on a 
special scale by means of the height which an albumen 
precipitate reaches when produced in a certain manner 
and allowed to stand twenty-four hours. The pre- 
cipitant, Essbach's reagent, is a solution of 10 g. picric 
acid and 20 g. citric acid in 1 liter of water. The 
albuminometer — it generally costs with directions 50 
cents — is nothing other than a test-tube made of strong 
glass having a scale and letters. The tube is filled with 
urine to the point U. so that the point and the meniscus 
of the liquid coincide, and then to the point R with 
the reagent. The tube is now closed with a good stopper, 
shaken not too violently ten or twelve times, and then 



38 THE PRAXIS OF URINARY ANALYSIS. 

allowed to stand upright. After twenty-four hours 
the volume of the precipitate is read off on the special 
scale. The reading gives the quantity of albumen in 
the urine directly in tenth per cents. If urines are 
very rich in albumen, and the scale of the apparatus 
does not extend far enough for direct readings, they 
are diluted in the tube one-half or one-third before 
making the test. For this also there are graduations. 
The actual albumen percentage is then found by simple 
multiplication. If the urine which is to be tested does 
not react acid towards litmus-paper, it is acidified with 
a trace of acetic acid. 

2. Quantitative Determination of Sugar. 

1. Sugar is determined quantitatively in a purely 
chemical way by titration with Fehling's solution. 
This method is really only suitable for chemical labor- 
atories. In the first place Fehling's solution must always 
be freshly prepared from its constituents, which are 
kept separately in the necessary concentration, since 
the mixture spoils on standing; secondly, and this 
is much more annoying, it is extremely difficult to 
determine the end of the reaction, for solutions of the 
proper strength can be bought nowadays. Only those 
who are engaged regularly in the titration of sugar in 
urine by this method can do this with complete certainty. 

2. The quantitative estimation of sugar in urine by 



URINARY ANALYSIS. 39 

fermentation. If a urine containing sugar is shaken 
with yeast the latter readily causes fermentation to set 
in and the sugar to break up into alcohol and carbon 
dioxide : 

C 6 H 12 6 - 2C 2 H 6 + 2C0 2 

1 molecule 2 mol. 2 mol. 

grape-sugar. alcohol. carbonic 

acid. 

If the quantity of carbonic acid gas evolved in twenty- 
four hours is then read off in the so-called fermentation 
saccharometers, which can be bought cheaply every- 
where, its volume is supposed to correspond to a definite 
amount of sugar. The saccharometers are graduated 
in per cents, and accompanied with full directions for 
use. The quantitative results of this method are 
very inaccurate. 

3. The estimation of sugar in urine is made by far 
most accurately and conveniently with a polariscope in 
which the dextro-rotation caused by grape-sugar is read 
off. It is only to be regretted that such instruments 
are so expensive. Since albumen also effects polarized 
light (lsevo-rotation), urines containing albumen must be 
freed from it in the usual way before polarization. The 
directions for using polariscopes — there are a number 
of constructions in use — need not be given here. Those 
instruments are most convenient which have a direct 
reading-scale in per cents, of grape-sugar, so that it is 
unnecessary to consult a table for the amount of sugar 
corresponding to the angle of polarization. 



40 THE PRAXIS OF URINARY ANALYSIS. 

It is of interest to us, however, to know how to 
decolorize urines, for most of them are too dark to 
permit an accurate adjustment of the polariscope, 
which is necessary for taking a reading. 

The author decolorizes urines as follows: \ cc. of the 
very best washed blood-charcoal, as obtained com- 
mercially, is placed in a test-tube and this then almost 
filled with the urine and the whole shaken thoroughly. 
On filtering, a liquid is obtained which is generally as 
colorless as distilled water. The objection which was 
formerly urged against animal charcoal, i.e., that it 
retained appreciable quantities of grape-sugar, and 
that hence by this method of decolorization the per- 
centage of sugar in urine was reduced, can be dismissed 
as irrelevant when so little of such charcoal is needed. 

Urines can also be clarified by shaking them with a 
small piece of lead acetate or by adding a solution of 
lead acetate or vinegar of lead. When using the 
last two methods the urine is diluted and this dilution 
must be taken into account, which is not necessary 
when employing animal charcoal or solid lead acetate. 

3. Determination of Total Sulphuric Acid and Ester 
Sulphuric Acids. 

The quantitative determination of the total sulphuric 
acid and ester sulphuric acids also requires several 
laboratory equipments and an analytical balance. 



URINARY ANALYSIS. 41 

We append the method here on account of the diagnos- 
tical importance which it has obtained, and because the 
chemists or apothecaries, to whom the physician must 
in most cases refer the analysis, will hardly find the 
method of its determination mentioned in any one of 
their analytical works. 

It is of interest to the physician to know not only 
the amount of ethereal sulphuric acids in a urine, but 
also its relation to the total sulphuric acid. The esti- 
mation of both varieties is made. 

Total sulphuric acid is determined as follows: 50 cc. of 
the filtered urine are acidified strongly with concentrated 
hydrochloric acid (3 to 5 cc.) and heated to boiling. 
The liquid becomes of a dark-red color. Barium 
chloride solution which has been heated to boiling in 
a test-tube is now added; this, curiously enough, 
causes considerable frothing of the liquid. Hence a 
medium-sized beaker should be used. 

The mixture is then suspended from six to eight hours 
in a boiling water-bath and allowed to stand over 
night, if possible, and filtered. Only by this procedure 
can the danger be avoided of the barium sulphate 
going through the filter, especially when the filter is 
first washed. The use of boiling barium chloride 
solution considerably minimizes this. The precipitate 
of barium sulphate is then treated in the usual manner. 

The so-called alkaline barium chloride solution is 



42 THE PRAXIS OF URINARY ANALYSIS. 

necessary for the determination of ethereal sulphuric 
acids. It is made by mixing together two volumes of a 
cold saturated barium hydrate solution with one 
volume of a cold saturated barium chloride solution. 
100 cc. of this mixture is added to 100 cc. of urine. The 
copious precipitate that is formed soon subsides and the 
clear supernatant liquid is poured through a fluted filter. 
The filtrate now contains, of substances that concern 
us, only the ester sulphuric acids and, besides, con- 
siderable barium hydrate and chloride, as all the free 
sulphuric acid is precipitated. 100 cc. of the filtrate, 
which are obtained very quickly, and which represent 
50 cc. of urine, are acidified strongly with hydrochloric 
acid and boiled for some time. The liquid acquires 
a dark-red color and gradually becomes turbid by 
the precipitation of barium sulphate whose quantity 
represents the amount of ester sulphuric acids. The 
heating is continued for six to eight hours on the water- 
bath and the precipitate is filtered off, preferably after 
allowing the solution to stand twenty-four hours. The 
precipitate is then washed, dried, ignited, and weighed. 
The ratio of ester sulphuric acids to total sulphuric 
acid in normal urine is about as 1 : 10. 



URINARY ANALYSIS. 43 

C. 

NORMAL URINE. 

Normal urine is a pale-yellow or amber-colored fluid. 
When drink is partaken of sparingly the color can 
change to a red-brown on account of the greater con- 
centration. Whether this last-mentioned color is 
normal or not is decided by the methods already given. 

Generally fresh urine reacts acid towards litmus. 
This acid reaction depends upon acid salts (particu- 
larly diacid phosphate), never upon free acids. 

Even fresh urine which reacts acid contains small 
quantities of mucous substances which on standing 
settle to the bottom in small clouds, and substances are 
always present in it which reduce an alkaline copper 
solution. 

Urine is decomposed by the action of bacteria when 
standing exposed to the air, and in cases of sickness 
already in the bladder. It becomes alkaline, clue to the 
decomposition of urea into carbonic acid and ammonia. 

The turbidity of urines, aside from the above-men- 
tioned unimportant slight clouds, can only be investi- 
gated microscopically. There are urines which appear 
not only turbid but thick (like soup). This turbidity, 
which often alarms persons, is caused by a copious 
quantity of acid sodium urate. This acid sodium 
urate is completely soluble at the body temperature in 



44 THE PRAXIS OF URINARY ANALYSIS. 

the voided urine. The urine is hence voided quite 
clear, but on cooling the urate is precipitated. This 
in itself is regarded as harmless and can easily be recog- 
nized by the fact that urine which is thus turbid becomes 
clear again when heated in a test-tube to the temperature 
of the body, or when sodium hydrate is added. The 
acid sodium urate which is difficultly soluble in water 
is hereby converted into an easily soluble neutral 
sodium urate. The slight turbidity which is noticed 
after this addition of sodium hydrate is caused by 
earthy phosphates, which every alkaline urine precipi- 
tates (see p. 39). Pathological components can be 
present besides the urates in the sediment, which must 
be examined under the microscope in the usual manner. 

Urines with strong, white, almost crystalline-looking 
precipitates occur less frequently. These are caused by 
neutral earthy phosphates. They can easily be recog- 
nized by adding several drops of acetic acid, when the 
turbidity disappears. 

The concentration of normal urine varies between 
1.002-1.030. When sugar is present in solution the 
specific gravity is increased to 1.040 and more. The 
specific gravity is determined with an areometer. These 
are made of a suitable length for this purpose and are 
called urinometers.* 

* Float the instrument in some rain or distilled water at the 
proper temperature (generally 60° F.) and see if the zero tallies. 



URINARY ANALYSIS. 45 

Normal substances occurring in urine are water, urea, 
uric acid, creatinine, xanthine substances, oxalic acid, 
ester sulphuric acids, hippuric acid, urobilin, and other 
coloring matters, pepsin, hydrochloric acid, sulphuric 
acid, phosphoric acid, sodium, potassium, ammonia, 
magnesium, calcium, iron. Besides the above there 
are a number of organic substances whose quantity- 
only amounts to hundredths of a per cent. 



II. 

ANALYSIS OF STOMACH CONTENTS. 

The analysis of the stomach contents which is to be 
given here deals with vomitings or the contents of the 
stomach of the patient as taken out with a stomach- 
pump, leaving completely out of consideration cases of 
poisoning. The object of the following investigation is 
to obtain, in cases of stomach troubles, certain reliable 
data for medical diagnosis by means of analysis. The 
chemical analysis of the stomach contents for diagnos- 
tical purposes can include only a very few substances. 

The contents are always first tested for free hydro- 
chloric acid. 

1. Test for Free Hydrochloric Acid. 

Filter the stomach contents and place a drop of the 
filtrate in a small porcelain dish. Now add two drops 
of Gunzburg's reagent and warm (not heat) the porce- 
lain dish by drawing it to and fro over a small flame, 

at the same time blowing over it with the mouth. As 

46 



ANALYSIS OF STOMACH CONTENTS. 47 

soon as the liquid in the dish begins to dry up a beautiful 
red color is seen around the edge if hydrochloric acid 
is present, which spreads still further as the liquid dries. 

Giinzburg's reagent is a solution of 1 part vanilline and 
2 parts phloroglucine in 30 parts of 96 per cent, alcohol. 
It is best kept on hand in small quantities in a small 
dropping-glass, which in turn is kept protected from 
the light in a pasteboard case. When exposed to the 
light the mixture gradually becomes dark-colored, 
but if kept in the dark it only turns wine-red, which does 
no harm. Besides, the alcohol evaporates much slower 
from the opening in the dropping-glass when it is kept 
in a case, and the reagent remains fit for use a year or 
more. 

The usual methods for the detection of hydrochloric 
acid by testing for the chlorine in the acid cannot be 
used here because combined hydrochloric acid is also 
present in the form of chlorides, i.e., sodium chloride. 

Aside from the fact that Giinzburg's method is the 
safest for determining free hydrochloric acid in the 
stomach contents, it affords the particular advantage 
over all other methods that only one drop of the filtrate 
is needed. This is the more important because many 
stomach contents filter badly. 

In order to become acquainted with the behavior 
of a dilute hydrochloric acid solution towards Giinz- 
burg's reagent a .2 per cent, solution is used (about as 



48 THE PRAXIS OF URINARY ANALYSIS. 

strong as the hydrochloric acid in a normal stomach). 
This solution may be further diluted for practice until 
the limit of sensibility of the reaction is reached. 

2. Detection of Lactic Acid. 

Add to the filtered gastric juice which fills a test-tube 
about one-fourth full, several cubic centimeters of a 
ferric chloride solution which has been diluted in a test- 
tube until the color is hardly visible. If this addition 
gives a canary-yellow color to the mixture lactic acid is 
present. Should no lactic acid be detected in this way 
the reason for this may be that it is present in too small 
quantity in the gastric juice for this direct method. 
In this case fill a test-tube three-fourths full with the 
filtered juice, add some ether and shake thoroughly; 
an emulsin will hardly ever be formed. When the 
ether, which contains the lactic acid, has separated, 
pour it off into a small porcelain dish, pour fresh ether 
into the test-tube, and repeat this procedure two more 
times. The ether in the dish is evaporated on a water- 
bath. Since the quantity of ether is small the dish 
may also be placed on a double-wire gauze and a very 
small flame placed under it. Care must be taken that 
it does not catch fire. The residue remaining after 
evaporating the ether must not be overheated (burnt). 
The last trace of ether is hence evaporated by blowing 
on it with the mouth. Two or three drops of water are 



ANALYSIS OF STOMACH CONTENTS. 49 

added to the residue and the diluted ferric chloride 
solution added. The presence of lactic acid will be 
proven in this case also by the appearance of the yellow 
color, which is due to iron lactate. This can be seen 
very well on the white background of the dish. The 
absence of lactic acid is shown by the absence of a 
yellow color. 

A lactic acid solution containing about .2 per cent, of 
the acid is used for practicing the reaction, and can be 
diluted further. 

If hydrochloric acid has been found in the stomach 
contents, one can be satisfied with this favorable result. 
If the acid is absent and lactic acid is found instead, or 
is also not present and only volatile acids are present 
(see below), a microscopic investigation in addition to the 
chemical analysis is indispensable (particularly for 
yeast, sarcinse, bacilli). 

3. Detection of Volatile Acids. 

Filter the gastric juice in which neither hydrochloric 
nor lactic acid has been found and distill as much of the 
filtrate as can be obtained. The distillate is tested 
with litmus-paper for acid reaction. The first drops 
will give this reaction if volatile acids are present; 
it is therefore not necessary to continue long the dis- 
tillation. A whole series of volatile acids (formic, etc.) 
distills over, which cannot be separated, nor is this 



50 THE PRAXIS OF URINARY ANALYSIS. 

necessary. Butyric acid particularly shows its presence 
by its sweaty odor. To practice this last reaction add 
of course a few drops of formic acid, butyric acid, etc., 
to some water and distill. 

Artificial Stomach Contents. — After these reactions 
have been learned, it is preferable to make the tests with 
artificial stomach contents instead of with dilute acids. 
To prepare these contents dissolve some commercial 
peptone in water (peptone is albumen which has become 
soluble in water by being digested). Such a solution 
foams considerably when shaken and does not become 
clear by filtering. This is a property of peptone and 
explains why gastric juice gives no clear filtrate. It 
becomes clear when alkali is added, i.e., as required by 
Trommer's test. To the peptone solution add some 
grape-sugar solution and thereupon some hydrochloric 
acid, lactic acid, and volatile acids according to the tests 
that are to be made. The observation will be made 
that slight quantities of added hydrochloric acid cannot 
be detected with even so delicate a reagent as that of 
Gtinzburg's. The reason for this is that the peptone 
unites with the hydrochloric acid to form a compound 
in which the latter is not detectable as free acid. Hence 
the stomach contents of a patient should not be tested 
shortly after a meal rich in albumen, or after milk has 
been drunk; the albumen of the latter is very quickly 
peptonized in the stomach. Several hours should 



ANALYSIS OF STOMACH CONTENTS. 51 

intervene after such a meal. After this time a normal 
stomach will again contain free hydrochloric acid. 

If Trommer's test is applied to the gastric juice a 
violet solution is first obtained, and this coloration 
establishes the presence of peptone, since it is caused 
by it. 

If this alkaline liquid containing cupric oxide is 
boiled, red cuprous oxide, but never yellow cuprous 
oxide, is precipitated, since grape-sugar is present. The 
grape-sugar in natural gastric juice can have been eaten 
as such or the ptyalin of the saliva has made it from 
starch. The gastric juice does not invert starch; this 
process occurs in the intestinal digestion. The violet 
color caused by the presence of peptone is not changed 
by boiling. 

4. Test for Absence of Pepsin. 

If hydrochloric acid has been found in a stomach 
content a poor digestion may be due to a lack of pepsin, 
for normal digestion is the mutual action of these two 
substances. To decide whether there is a lack of 
pepsin, which is said to be extremely rare, proceed as 
follows : 

Divide the filtered gastric juice into three parts and 
place in each a piece of fibrin. No. 1 is used for a 
blank determination, No. 2 receives some .2 per cent, 
hydrochloric acid, and No. 3 some commercial pepsin. 



52 THE PRAXIS OF URINARY ANALYSIS. 

All three samples are placed in a warming-closet 
heated to 38°-40°. In the course of an hour it can 
be easily discerned which portion has dissolved the 
most fibrin, i.e., digested it. If this is the case with the 
sample to which pepsin w r as added there was a lack 
of pepsin in the original gastric juice. 

Fibrin is used because this is the most easily digestible 
solid albumenoid for artificial digestion experiments. 
It is obtained by allowing fresh blood to stand a short 
time. A solid red-colored mass is soon separated from 
it, which the blood is capable of retaining in solution 
only so long as it circulates in a living body. When 
this mass is washed with water it loses its red color and 
has been given the name fibrin. As fibrin soon de- 
composes, it is kept best by pouring on it in a glass 
some water containing considerable glycerine. Thus 
treated it will keep a long time. Before use the glycerine 
is washed out with water. Finely cut slices of a hard- 
boiled egg can be used when no fibrin can be had, but it 
is digested much more slowly. It does not come within 
the scope of this book to test for the propeptone and 
peptone which are formed from the albumenoids by 
such digestions, for such a test cannot claim any 
particular diagnostical value. 



REAGENTS AND APPARATUS. 



ALPHABETICAL LIST OF ALL THE NECESSARY 
REAGENTS. 

Acetic acid (10 per cent.). 

Acetoacetic ethyl ester. 

Acetone. 

Alcohol. 

Ammonia. 

Amyl alcohol. 

Animal charcoal. 

Barium chloride (10 per cent, and cold saturated solution). 

Barium hydrate solution (cold saturated). 

Blood. 

Butyric acid. 

Calcium chloride solution. 

Chlorated lime solution (very dilute). 

Chloroform. 

Citric acid. 

Copper sulphate solution (5 per cent.). 

Ether. 

Faeces. 

Ferric chloride (solid and 5 per cent, solution). 

Fibrin, or egg-albumen. 

Glacial acetic acid. 

Grape-sugar. 

Horses' urine 

53 



54 REAGENTS AND APPARATUS. 

Hydrochloric acid (25 per cent, and 36 per cent.). 

Infusorial earth. 

Lactic acid. 

Lime milk. 

Nitric acid (25 per cent, and fuming). 

Pepsin. 

Peptone. 

Phloroglucine. 

Picric acid. 

Potassium ethyl sulphate. 

Silver nitrate solution (3 per cent.). 

Sodium carbonate solution (10 per cent.). 

Sodium hydrate (10 per cent, solution). 

Sodium nitroprusside. 

Vanilline. 

Zinc chloride solution (alcoholic 5 per cent.). 

REAGENTS NECESSARY FOR URINARY ANALYSIS. 

General preservation of urines . . . Chloroform. 

Albumen test 10 per cent, acetic acid. 

Infusorial earth. 

Artificial albumen urine Egg-albumen. 

Artificial earthy phosphate urine . Calcium chloride solution. 

Soda solution. 
Sugar test 10 per cent, sodium hydrate so- 
lution. 
5 per cent, copper sulphate so- 
lution. 

Artificial sugar urine Grape-sugar solution. 

Sodium nitro-prusside. 
Acetone test 10 per cent, sodium hydrate so- 
lution. 
Glacial acetic acid. 

Artificial acetone urine Acetone. 

Acetoacetic acid test 5 per cent, ferric chloride solution. 

Artificial acetoacetic acid urine. . Acetoacetic ethyl ester. 

Bile-pigment test 95 parts of 25 per cent, nitric 

acid mixed with 5 parts fuming 
nitric acid and 30 parts water. 



REAGENTS AND APPARATUS. 55 

Urobilin test , Hydrochloric acid. 

Amyl alcohol. 

96 per cent, alcohol. 

5 per cent, alcoholic zinc chloride 
solution. 

Ammonia. 
Artificial urobiline urine Faeces. 

96 per cent, alcohol. 
Blood test 10 per cent, sodium hydrate so- 
lution. 

Artificial blood urine Fresh or dried blood. 

Indican test Dilute chlorated lime solution. 

25 per cent, hydrochloric acid, 

(or) 

Solid ferric chloride. 

36 per cent, hydrochloric acid. 

Chloroform. 
Artificial indican urine Horses' urine. 

96 per cent, alcohol. 
Sulphuric acid test . 10 per cent, barium chloride so- 
lution. 

Hydrochloric acid. 
Ester sulphuric acids 10 per cent, barium chloride so- 
lution. 

10 per cent, soda solution. 

25 per cent, hydrochloric acid. 
Artificial urine with ester sul- 
phuric acids Potassium ethyl sulphate. 

Chlorine test Nitric acid. 

3 per cent, silver nitrate solution. 
Ammonia test Milk of lime. 



REAGENTS AND APPARATUS REQUIRED FOR QUANTI- 
TATIVE URINARY ANALYSIS, ETC. 

Determination of albumen Essbach's albuminometer. 

Essbach's reagent, 5 g. picric 
acid, 10 g. citric acid dissolved 
in one-half liter of water. 

LofC. 



56 REAGENTS AND APPARATUS. 

Determination of sugar Fermentation saccharometer. 

Polarizing apparatus. 
Animal charcoal. 
Determination of total sulphuric 

acid and ester sulphuric acids . . 25 per cent, hydrochloric acid. 

10 per cent, barium chloride so- 
lution . 
Alkaline barium chloride solution 
(mixture of two parts of cold 
saturated barium hydrate solu- 
tion and one part cold satu- 
rated barium chloride solution) . 
Determination of the specific 

gravity Ureometer. 



REAGENTS NECESSARY FOR THE ANALYSIS OF THE 
STOMACH CONTENTS. 

Test for hydrochloric acid Gunzburg's reagent. 

1 part vanilline and 2 parts 
phloroglucine in 30 parts or 
96 per cent, alcohol. 
Test for lactic acid Very dilute ferric chloride solu- 
tion. 

Ether. 
Artificial stomach contents Peptone. 

Grape-sugar. 

Hydrochloric acid. 

Lactic acid. 

Butyric acid. 
Digestion experiment Filtered gastric juice. 

0.2 per cent, hydrochloric acid. 

Pepsine. 

Fibrine (or hard-boiled egg). 



INDEX. 



PAGE 

Acetoacetic acid 19, 20 

Artificial acetoacetic acid urine 21 

Acetone. 19 

Artificial acetone urine 20 

Albumen, qualitative test 11 

quantitative estimation 37 

Artifici I albumen urine 13 

Ammonia of urine 35 

Bile-pigment 21 

Artificial bile-pigment urine 22 

Blood-pigment 24 

Artificial blood-pigment urine 25 

Chlorine 32 

Ester-sulphuric acids, qualitative test 28 

" " quantitative estimation 41 

Artificial ester -sulphuric acid urine 31 

Gunzburg's reagent 47 

Hydrochloric acid, test for 46 

Indican 25 

Artificial indican urine 27 

Lactic acid, test for 48 

Normal urine . 43 

Pepsin, test for absence of 51 

Phosphates of urine 32 

Artificial phosphate urine 14 

Stomach contents 46 

Artificial stomach contents 50 

57 



58 INDEX. 

PAGE 

Sugar, qualitative test 15 

" quantitative estimation 38 

Artificial sugar urine 18 

Sulphuric acid, qualitative test 28 

" " quantitative estimation 40 

Trommer's test 13 

Urobilin 22 

Artificial urobilin urine 23 

Volatile acids, test for 49 



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